Liquefied petroleum gas dispensing system



Oct. 28, 1941.

L. J. WHITE LIQUEFIED PETROLEUM GAS DISPENSING SY STEM Filed Jan. 17, 1940 Patented Oct. 28, 1941 LIQUEFIED PETROLEUM GAS DISPENSIN SYSTEM Loyd J. White, Saii" Antonio, Tex., assignor to Southern Steel Company, San Antonio, Tex., a corporation of Texas Application January 17, 1940, Serial No. 314,312

Claims. (01. 62-1) This invention relates to liquefied petroleum as systems for storing and generating liquefied petroleum gases, such as mixtures of butane, isobutane, propane and other-more or less volatile petroleum constituents and, among other objects, aims to provide a greatly improved underround system of the general type disclosed in Patent No. 2,176,829, wherein the gas is delivered in the liquid phase from a pressure storage idly than butane, isobutane and the other less volatile components. When the fuel mixture contains or more of propane, for example, the variation in the B. t. u. content of the generated gas between a full and a nearly empty tank is so great that uniform and the most efli cient combination cannot be obtained without adjusting the air supply to the burners. The present invention overcomes this and other difficulties by providing a greatly improved, compact, liquid eduction system which delivers dry gas of substantially uniform heating value at all. times, regardless of the mixture used and the liquid level in the tank.

tank and is vaporized after a first stage pres- 10 Referring more particularly to the drawing, sure reduction and the gas vapor is then subthe Syste t e e Sho e b an Underjected to a second stage pressure reduction, ground pressure storage tank l0 having a standeady for consumption in the usual gas applipipe II, to the top of which is connected a uniances. The main idea is to provide in a liquid ary valv d fit in a liq i eduction p eduction system of this type a novel heat ex- 15 passing through the S n pipe nd being changer in the delivery conduit between two nected to the fitting to dis h r liq gas pressure reducing regulators and associated through a cutoif valve M to an outlet nipple IS, with the storage tank acting as a flash gas genll a ra ged in a protecting casi 6 a d erator to insure a continuous supply f dry gas ing the same as disclosed in the aforesaid patof uniform heating value, regardless of the 0 amount of fuel in the tank. Another aim of the In this i stance, a c phav d w e heat invention is to provide a composite two-stage changer I1, pr y k t s w n y pressure reduction system of this type adapted copending application Ser. No. 276,024, filed May to be factory assembled and having h at 26, 1939, is connected to one end of the tank changing means on the tank for supplementing ID to supplement the vaporizing heat of the the heat of the earth in vaporizing the contents earth and thereby create a vapor pressure in. of the tank to create the liquid eduction presthe tank which forces the liquid out of the tank. sure, and also acting as a flash vapor generator Associated with the heat exchanger is a cupfor the liquefied gas after it passes through the shaped flash chamber or generator '8 pr f r first stage pressure regulator, as well as to reof the same size as and forminga continuation vaporize any condensate which may be formed of the heat exchanger l1 so that the end wall in the gas service pipe. IQ of the heat exchanger separates it from the other aims and advantages of the invention flash chamber and the heat is thus transferred will appear in the specification, when considered m o o the Otherin connection with the accompanying drawin The liquefied gas delivered through the outlet wherein: nipple l5 passes through a first stage pressure Fig. l is a vertical sectional view, partly in regulator 20 and a pipe 2| to the flash chamber elevation, showing a system embodying the in- Hi, the regulator 20 being preferably set to revention; and duce the pressure to about 5 pounds. The liquid Fig. 2 is a left end elevation of Fig. 1; and is qui y n t d n vapor in t flash Fig. 3 is a fragmentary view of a modified chamber due to the contained heat at the lower form of heat exchanger. pressure and the rapid absorption of additional In underground systems of the type which disheat from both the heat exchanger and the sur- Dense liquefied gas in the gas-phase from the un g e O t e C mbe the gas storage tank by batch vaporization therein, vapor passes through a pipe 22 carrying a seeit is well known that there is an appreciable dif- 0nd stage reg a or 23 Of the usual yp ference between the B. t. u. content of the gas .ranged within the protect n as Which coming from a full tank and a nearly empty tank delivers the gas at a pressure of about 6 ounces because the more volatile components of the o t e e e c u t 24 leading u de eu mixture, such as propane, vaporize more rapto the point of use. The service pipe is shown as passing over the heat exchanger. and has a depending re-vaporizing spur tube or condensate trap 25 extending into the heat exchanger as disclosed in the aforesaid copending application.

i there is shown and the pipes 2| and appurtenances when system, a pressure ground" below the I pipe connected to j vof -the-storage tank; an external water heat ex- 1 1 ground below the frost line; an

To. relieve any excessive pressure which may "develop in the pipe 2| between theregulators,

an ordinary pressure relief valve 26 within the casing to discharge'through it to 3 the atmosphere. Also, the second stage regulator 23 is shown as having the usual pressure relief valve 21 on the low pressure side vented through [a vent tube 28 leading to a point near the top of the casing.

In Fig. 3, there is shown a modified form of gas generator placed in the water heat ex-' changer.

the water chamber than the chamber H In this example, I1 is shown as being larger 29 submerged in the water within the chamber l'l. The coil serves the same purpose as the flash generator or chamberv l8 in Fig. 1.

From the foregoing description, it will'be seen.

that the improved system is very compact in design and canbe. assembled complete and tested at the factory at a relatively low cost. It is easy,- to install and does not require any expert gas fltterto connect and adjust regulators and other jectionable variations in richness of gas generated from blends-or mixtures of butane, propane and other volatile petroleum constituents. I

1 Obviously, the present invention is not restricted to, the particular embodiment thereof ground below the frost line; an external heat exchanger associated with the tank; a liquid eduction pipe connected to and leading from the bottom oflthe storage tank; a pressure reducing valve in the liquid eduction pipe; a vapor generator associated with said heat exchanger connected to vaporize the liquefied gas at the reduced pressure and deliver it to a service pipe;

a pressure reducing regulator connected to the service pipe; and a casing above the tank housing both the pressure reducing valve and the preS- I sure regulator.

22"are connected to a coil the installation is made. It has fully demonstrated that it will overcome obherein shown and described. Moreover, it is not v indispensable'that all the featu'resof the invene tion-be used conjointly, since they may be employed advantageously in various combinations 3 and sub-combinations.

What is claimed is: g e 1. In an underground liquefied gas dispensing a pressure storage tank buried in the I vapor generator associated 'with'said heat exchanger connected to I Ivaporize' the liquefied gas at the reduced pressure and deliver it to a service pipe.

2. In-an underground liquefied gas dispensing storage tankburied in the 'frost line; a liquid eduction and leading from the bottom changer secured to the tank to supply supplemental'heat to the tank and maintain liquid eduction vapor pressure therein; a fiash vapor "generator connected to the eduction pipe and associated with the heat exchanger; a pressure reducing-valve in the eduction pipe between the tank and the flash generator; and a vapor conduit leading from the flash generator.

3. In an underground liquefied gas dispensing system, a pressure storage tank buried in the external heat exchanger assembled on' the tank; a liquid eduction pipe-connected to and leading from the bottom I of the storage tank; a pressure reducing valve in the liquid eduction pipe; a' vapor generator associated with said heat exchanger connected to vaporize the liquefied gas at the reduced pressure and deliver it to a service pipe; and a pressure reducing regulator connected to the service pipe.

4. 'In an underground liquefied gas dispensing system, a pressure storage tanklburied in-the mental heat to the tank and maintain liquid 5. In an underground liquefied gas dispensing system; a cylindrical pressure storage tank buried horizontally in the ground below the frost line; a heat exchanger integrally connected to one end of the tank;,a liquid eduction pipe connected to and leading from the bottom of the storage tank; a pressure reducing valve in the liquid eduction pipe; a vapor generator associated with said heat exchanger connected to vaporize the liquefied gas at the reduced pressure and deliver it to a service pipe; a pressure reducing regulator connected to the service pipe; a casing above the tank housing both the pressure reducing valve and the pressure regulator; and pressure relief valves on the lowpressure sides of the pressure reducing valve and the regulator also arranged within said casing. A

I 6. In an underground liquefied gas dispensing system, a pressure storage tank buried in the ground below the frost line; a liquid eduction pipe connected to and leading from the bottom of the storage tank; an external water heat exchanger secured to the tank to supply suppleeduction vapor pressure therein; a flash vapor generator connected to the eduction pipe and associated with the heat exchanger; a pressure reducing valve in the eduction pipe between the tank and the flash generator; a vapor conduit leading from the flash generator; and a pressure reducing regulator in the vapor conduit adjacent to the tank.

'1. In an underground liquefied gas dispensing system, a pressure storage tank buried in the ground below the frost line; a cup-shaped heat exchanger secured to one end of the tank and carrying a ,heating medium; a liquid eduction pipe connected to and leading from the bottom of the tank; a cup-shaped extension on the heat exchanger providing a flash generating chamberconnected to the liquid eduction pipe; a pressure reducing valve in the liquid educ-' tion pipe; a gas delivering pipe connected to the generating chamber; and a pressure reducing regulator in the gas delivery pipe. 8. In an underground liquefied gas dispensing system, a pressure storage tank buried in the ground below the frost line; a cup-eshaped heat exchanger secured to one end of the tank and carrying a heating medium; pipe connected to and leading from a liquid eduction the bottom of the tank; a cup-shaped extension on the heat exchanger providing a flash generating chamber-connected to the liquid eduction pipe; a pressure reducing valve in the liquid eduction pipe; a gas delivering pipe connected to the generating chamber; a pressure reducing regulator inthe gas delivery pipe; and re-vaporizing means connected to the gas delivery pipe beyond the regulator and associated with the heat exchanger.

' r 9. In an underground liquefied gas dispensing system, a pressure storage tank buried in the ground below the frost line; a cup-shaped heat exchanger secured to one end of the tank and carrying a heating medium; a liquid eduction pipe connected to and leading from the bottom of the tank; a vapor generating coil in said heat exchanger connected to the liquid eduction pipe; a gas delivery pipe also connected to the coil; and pressure reducing regulators in both the liquid eduction and gas delivery pipes.v

10. In an underground liquefied gas dispensing system, a pressure storage tank buried in the ground below the frost line; a cup-shaped heat and a casing above the tank housing both of 10 said regulators.

LOYD J. WHITE. 

